B2 Bluetooth Audio Transmitter Adapter 1. Plug and play—no software drivers required 2. Dual-stream transmission (TX mode): Connect two Bluetooth speakers or headphones simultaneously using one codec; supports aptX Low Latency 3. Multipoint connection (RX mode): Connect two mobile phones 4. Features a high-performance Bluetooth chip 5. One-button mode switch between RX and TX 6. Low-battery indicator activates below 20% charge. Automatically enters power-saving sleep mode after 6 minutes of inactivity in either RX or TX mode. Built-in battery protection circuit for safe and reliable charging 7. RCA and I2S audio input/output interfaces—freely switchable 8. Dual-antenna design enables stable Bluetooth connectivity up to 80 meters 9. High-fidelity audio with ultra-low latency; supports aptX Low Latency, aptX, SBC, AAC, and other standard codecs 10. Automatic reconnection in both RX and TX modes; remembers previously paired devices 11. Operating frequency: 2.402–2.480 GHz 12. Input/output options: RCA interface, I2S/AUX interface; supports simultaneous RCA and AUX output 13. Battery capacity: 500 mAh 14. Data transfer rate: 2.4 Mbps 15. Working frequency band: 2.402–2.480 GHz 16. Battery life: Up to 10 hours in RX mode, up to 8 hours in TX mode 17. Charging time: Approximately 2.5 hours 18. Supported Bluetooth profiles: RX—A2DP, AVRCP; TX—A2DP 19. Bluetooth version: 5.0 20. Charging interface: Micro USB (5 V / 0.5 A) 21. Charging power: 2.5 W 22. Dimensions: 11 × 9 × 2.5 cm 23. Weight: 70 g Package includes: - USB charging cable × 1 - 3.5 mm audio cable × 1 - RCA audio cable × 1 - User manual × 1